Car sharing is changing the way drivers rent cars, especially in big cities where the trend has caught on. City residents and businesses alike - often with some disposable income but not enough to own a car of their own - have taken to the idea of renting one for a few hours of shopping, to tour clients around, or to use for an afternoon drive into the country.

In New York, the Boston-based company Zipcar has dominated the car sharing cottage industry thus far. Long Island-born entrepreneur Richard Ull, however, is hoping this will change with his recent expansion of Mint, another car sharing company with a new set of perks that could attract plenty of customers.

Already the company, which was launched in the fall of 2008 and rents roughly 25 cars from several Manhattan locations, has over 2,000 members. Ull believes this number will grow significantly with the May 1st opening of branches in Brooklyn Heights and Park Slope.

"Because of all the dynamics of Brooklyn, that was the ideal location to [expand] to," said Ull, who until now has operated Mint out of Manhattan only. In studies made before the move, Ull said Brooklynites were receptive to a competitor to Zipcar.

The difference between Mint and Zipcar - indeed between Ull's company and any other that might pop up in the city - is in the unique way Ull has incorporated his own network of parking garages into the car sharing business model, allowing him to lower the cost of renting cars by the hour.

Ull's family's parking garage business owns more garages in Brooklyn than any other parking operator. Ull owns and operates over 50 parking facilities across the city.

To rent a car from Mint, all you have to do reserve one in advance online and then go to the nearest participating parking garage to pick it up. Because free parking is included in the price - as is gas and a basic insurance policy - Mint's cheapest models, ranging from the Smart Cars to Hondas and Toyotas, can rent for as little as $2 an hour.

In June, this jumps to $5 an hour, but even so, said Ull, Mint is 35 to 40 percent cheaper than the competition. The most expensive option, the higher end Mercedes Benz C-300, rents for just $13 an hour. Not bad, considering. The next time you want to impress an out-of-town guest (or a date) suit up, rent the Benz, and cruise the town.

I did just that, sort of, on a recent weekday morning. Traveling by subway to a parking garage in Manhattan, I picked up a Smart Car and, accompanied by a Mint representative, took the spunky mini for a spin to test the Mint experience. I drove it over the Brooklyn Bridge, tooled around downtown Brooklyn, and even braved the BQE, where we managed to survive without being crushed by normal-sized cars.

"Membership is growing very fast," said Ull. Clearly, he said, New Yorkers are excited to "finally have an alternative to Zipcar and, obviously, normal rental cars."

Ull said city residents have been drawn to his company as well for its commitment to improving the environment. Car sharing does indeed present a viable alternative to overcrowded city streets, though its adoption nationwide could still be years away. Ull cited the accepted industry-wide statistic that 40 to 50 people use a single car, resulting in a reduction in carbon emissions and traffic.

Riding in my Smart Car down the elevated highway, trying to outdistance a menacing tractor-trailer to my left, I felt no remorse at the thought of sharing the car with dozens of strangers.

Why not? As long as Mint keeps them clean (crews clean the company's still-new fleet three times a week) and filled with gas (like Zipcar, they come with gas and gas station charge cards), it doesn't matter how many people also use the thing to make the same trips to Fairway or Jones Beach.

To any skeptical eco-friendly Brooklynites who haven't yet warmed to the idea, Ull - who is planning to open a third Brooklyn location in Williamsburg later this summer to go along with his many participating parking garages - has two words: hybrid cars.

"We are in talks right now to get hybrids. Most likely we'll be introducing them in Brooklyn first," Ull said. "We're going to move with our membership." (For more information on Mint visit drivemint.com or call 212.206.8555)